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large generator question


806 man

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You are probably on the right track with a used genny and manual switch. Even with an automatic switch, there will be a starting delay during which your equipment will stop. You will have to restart the equipment so not a big deal to start the generator first. 

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?Also staggering your equipment restart to reduce your in rush load which can be 3-4 times as much as normal operations, also does your equipment have vfds on the conveyors and other? Some of the older ones don’t like power disruptions and go into faults...

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There are three ratings for generators. Standby, prime, and continuous. The difference between these ratings is the engine. The best way to explain it is with an example. If you put a corvette on a dyno and cranked it up to rated horse power and let it eat for 30 minutes you would ruin the engine. ( if it even made it 30 minutes ).

standby is the max the gen will do but it can only run at that load for a very short time. Prime is the safer level that it can run for hours. Continuous is the level it can run at for days. 

MultiQuip makes the best generator on the market in my opinion. Get the komatsu engine with the denyo alternator.

a generator is like a chain. It’s only as good as it’s weakest link. If you had the best generator made but the coolant sensor locks it out it’s worthless.

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I've been involved in the design (and some installation) of several generator projects overseas.  Mission compounds, the like.    Everything from (2) 20kw Cummins gensets, to a couple 1MW power stations set up for continuous duty (see dead-on comment above).  Mostly its about cooling, so running a standby unit at say, 50% for a couple days works OK.  For your need, I'd look for a "prime" power rated unit out of a Hospital or Airport.   

Here is a link to a company that specializes in new & rebuilt gensets:  https://martinenergygroup.com/inventory/   May give you a good feel for prices/etc.   These people are absolutely stellar to work with, they've donated a lot of time/resources to assisting the not-for profit work we have done.   Call them-- they can help you decide what you need.

If you go single unit----its simple but has a single failure point.   Multi-unit and you have to consider control systems for auto-syncing the gensets.   Lots of moving parts to fail.  Need a tech on hand 24-7 (daily for standby use?)   If you want UPS--- now you are talking a whole NOTHER level....large battery backup systems with instant transfer controllers (Actually at that point, it can almost more be considered an on-site power system that uses the grid as a primary source.) 

The last system we designed has (5) Cummins 855/Marathon 250KW gensets (limited in size by what can be manhandled with basic tools), and a 1MW Solar/battery system with Tesla battery packs.   Not built yet because of donor issues & then COVID hit.    

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5 hours ago, Jeff-C-IL said:

The last system we designed has (5) Cummins 855/Marathon 250KW gensets (limited in size by what can be manhandled with basic tools), and a 1MW Solar/battery system with Tesla battery packs.   Not built yet because of donor issues & then COVID hit.    

And here I thought this could be a simple project.

 

6 hours ago, MarkG said:

There are three ratings for generators. Standby, prime, and continuous. The difference between these ratings is the engine. The best way to explain it is with an example. If you put a corvette on a dyno and cranked it up to rated horse power and let it eat for 30 minutes you would ruin the engine. ( if it even made it 30 minutes

Most of the systems I look are 8-12 cylinder Cats I would think they would last. Not to many Prime advertised, See a lot of Standby with Prime rating. $55k will buy a low hour unit. More then likely just like every other project spend $500K on updates then the Electrician guy shows up an adds another $200-250K redoing stuff.?

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1 hour ago, 806 man said:

And here I thought this could be a simple project.

 

Most of the systems I look are 8-12 cylinder Cats I would think they would last. Not to many Prime advertised, See a lot of Standby with Prime rating. $55k will buy a low hour unit. More then likely just like every other project spend $500K on updates then the Electrician guy shows up an adds another $200-250K redoing stuff.?

It can be pretty simple. Don’t let these guys make it sound so bad. I would expect an 800amp 600volt 3ph 3R manual switch to cost at least $5K. An automatic switch could exceed $30K. Plus installation of either. Installation could vary a lot depending upon what must be done to install it. 
 

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On 1/17/2021 at 6:11 PM, J-Mech said:

I am more than happy to admit I am not a potato farmer, or processor.  Raised them in the garden several times, and we consume pounds of them at my house.  You must get them trucked in this time of year?  No matter, the thread is about generators, not potato processing. I don't need to know now.  Another time perhaps. 

Thank you for being a potato lover. ?  The only trucking is from our storage buildings to wash plant. In the photo there is 1 spud storage building. Looks like twins side by side with fan room on end, which blows air into the air plenum. this building has an air floor, which is tunnels under the main floor, the main floor has 5/8's''x10'' slots spaced across the floor which is what the spuds are piled on. Some buildings have 20'' pipes with 2 rows of 2.5'' holes the length of pipe for air which are laid 60' across the floor every 8-10' the length of building.

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4 hours ago, 12_Guy said:

It can be pretty simple. Don’t let these guys make it sound so bad. I would expect an 800amp 600volt 3ph 3R manual switch to cost at least $5K. An automatic switch could exceed $30K. Plus installation of either. Installation could vary a lot depending upon what must be done to install it. 
 

Today I checked on power we have 2x300 KVA boxes. If we lose power 1/2 a day that is fine, It's the freak storm that hits that takes us out for 1+ days is the concern. 5 years ago I added a auto switch at my house it was $15k for the switch and electrician. I did the trenching and conduit work before they showed up. Works like a dream, Power out 10 seconds it's running.

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Here are some pics of what the potato operations I used to service equipment for grew into. First is news report photo of inside of their newer storage buildings, second is photo of some of the potato storage, third photo is of shop and storage building of the old potato guy, I fixed a lot of jd tractors and semi trucks in that building, fourth photo is of original farm that where the irrigated land first started and fourth and fifth is photos of the pivot circles. There isn’t hardly one of those circles where I didn’t put a driveshaft back on a truck, rescue a lifeless vehicle or tractor or get his old 1480 running in a winter corn field. Was 4 different farms raising potatoes, corn and some cover crops now two farmers control it all. One plants potatoes other local guy rents and owns circles in off years for rotation crops. In the news report they said 100 million lb crop of French fry potatoes going to simplot in grand forks

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30+ years ago when ONAN was still king of the standby market, I worked for a small dealer in Richmond, VA. One of our clients was a US Coast Guard station on an island off the coast that had no electricity. They had 2 150K units and would run one continuously for 2 weeks, then shut it down, service it and run on the other one. The last time I was there we had to take a new generator end over there on a boat to replace one that either the armature or field had burned out on (can't remember which at this point but they wanted it all new) So each genset was getting about 5000 hours a year on it and they were about 10 years old at that point. The largest units we took care of was a pair of 1100kw v12 powered. They were back up power for a small manufacturing plant but were also grid tied and accessible to the power company for peak demand use. As mentioned above, a lot of back up units are changed out on an age basis and in my experience, the 100KW and up units do not command a large price in the resale market even though many have less than 1000 hours on them. GovDeals always has some if you want to see what they are bringing there. One thing no one has talked about, and maybe it's not a concern now, is poles vs RPM. A 2 pole generator needs the engine to run at 3600rpm's, a 4 pole, 1800 and a 6 pole 1200. Back in my day ONAN sold a budget 75kwish 2 pole diesel powered set that a lot of "budget minded" farmers bought. After working on 4 pole sets weeks at a time, when I started one of those, I usually shut it right back off thinking the throttle was stuck. Never saw one blow up, but a 6 cylinder diesel running at 3600rpm never seemed like a good idea. CAT was the only company I saw that made a 6 pole unit. We had one in a big hotel up on about the 10th floor in a mechanical room. Sounded like it was just idling when it was under full load. I'm by no means up on what's currently out there, but back in the day what you want to do was pretty routine.

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11 hours ago, dale560 said:

In the news report they said 100 million lb crop of French fry potatoes going to simplot in grand forks

Big picture 100,000,000 lbs sounds like a bunch until you look at tons. A company that size probably less then a months worth of product. The plant in Warden we haul culls run about 50-60 ton an hour 1,300-1,400 ton per day if they don't break down. Had truck sit there for 26 hours due to repairs.?

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3 hours ago, yellowrosefarm said:

One thing no one has talked about, and maybe it's not a concern now, is poles vs RPM. A 2 pole generator needs the engine to run at 3600rpm's, a 4 pole, 1800 and a 6 pole 120

I have noticed different RPM, most are 1,800 a few 1,200.  I thought it was more to do with the engine size . So what is a pole ? besides what you put in a round hole.

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1 hour ago, 806 man said:

I have noticed different RPM, most are 1,800 a few 1,200.  I thought it was more to do with the engine size . So what is a pole ? besides what you put in a round hole.

Practically speaking the poles are the bump out parts of the armature. With a 2 pole, there are 2 directly across from each other. With a 4, they are in a cross pattern, and a 6 like a Chevy wheel bolt pattern. Similar to how fan blades are arranged on their shaft. The electrical theory I'll leave to someone better able to explain it.

More poles, means more material to make it and thus more expense up front. The advantage is lesser RPM which should make everything last longer.  Most all small engine generators are 2 pole to take advantage of the 3600rpm engine. 4 poles take a larger engine as it has to power full load at 1800, or 1200 if a 6 pole. 

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What he said ^  

The engine speed and number of poles in the alternator determine the frequency of the output voltage. Here in the US we are using 60hz power. 1 hz is 1 cycle per second. A cycle is one complete alternation from 0 to positive back to 0 and then to negative and then back to 0 along a sine wave. At 60 hz the polarity changes or alternates 60 times per second or 3600 times per minute. Two poles north and south or positive and negative must pass through the wires in the alternator to create 1 hz or 1 alternation. Thus a 2 pole unit must run 3600rpm to create 3600 alternations per minute or 60hz. Similarly a 4 pole runs 1800 and a 6 pole runs 1200. Since it takes 2 poles per alternation or cycle a 6 pole has 3 pairs 3*1200=3600 per minute. 
 Think of a pair of poles as a bar type magnet attached perpendicularly to the rotating shaft. 
Generators used in other countries must provide 50hz power. They simply run slower.  Two pole runs 3000. Four pole runs 1500. 
Have I confused everyone yet??? 
You could possibly buy a 50 hz unit and speed it up. 

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Stay away from new machines that have the emissions stuff. The engine needs to have a load to regen the dpf filter. With the exercise option that runs it once a week the dpf can clog and not be able to regen. If it gets bad enough it has to be removed and sent off to be cleaned. Very expensive.

also if you have two 300 kva services that need power that does not mean you need 600 kw gen set. You need to size the generator for the actual load not the size of the service.

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We are trying to get two going that we got from a sawmill a few years ago. We got both engines to run now to switch from 440 to 208 . Hopefully we can get one working as our normal backup has quit working. This is the bigger one it's got a 608 hp Deutz engine on it ..... 

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33 minutes ago, bitty said:

We are trying to get two going that we got from a sawmill a few years ago. We got both engines to run now to switch from 440 to 208 . Hopefully we can get one working as our normal backup has quit working. This is the bigger one it's got a 608 hp Deutz engine on it ..... 

IMG_20210119_164848639.jpg

IMG_20210119_164854824.jpg

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That’s a beast! Glad I don’t have to feed it. There should be a connection diagram that would show how to reconnect the voltage. It’s probably a normal 12 lead alternator. Worst part is if it has a breaker for the output it will have to be bigger if you expect full capacity. 

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On 1/18/2021 at 10:05 AM, MarkG said:

There are three ratings for generators. Standby, prime, and continuous. The difference between these ratings is the engine. The best way to explain it is with an example. If you put a corvette on a dyno and cranked it up to rated horse power and let it eat for 30 minutes you would ruin the engine. ( if it even made it 30 minutes ).

standby is the max the gen will do but it can only run at that load for a very short time. Prime is the safer level that it can run for hours. Continuous is the level it can run at for days. 

MultiQuip makes the best generator on the market in my opinion. Get the komatsu engine with the denyo alternator.

a generator is like a chain. It’s only as good as it’s weakest link. If you had the best generator made but the coolant sensor locks it out it’s worthless.

I use my 175kw 3 or 4 days a week, about 7 hours a day. It is a stand by  and rated for 150 kw steady load. The engine is a 270 hp Cummins 8.3 turbo [C series] I worry about using it too much but I am told the engine will outlast the gen.

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the mill we service had a 250KW caterpillar, that one was setup at 480V. the generator worked alright but it is a big deal to maintain, and to operate and to of course purchase.  if you have multiple buildings, multiple stations are there certain ones that can run while the others do not? for instance can you be unloading and stock piling even while you aren't cleaning and sorting? if you can prioritize activities it might bring your generator needs way down to a more manageable size? keep in mind once you get into these units you are into some next level maintenance cost. that generator had a 275 gallon tank for engine oil, which needed to be changed at an alarming frequency, don't even get me started on fuel consumption. keep in mind these things are running wide open 100 percent off the time they are running. before you consider this, I would contact a company like Cat and get some numbers on maintenance and fuel cost and evaluate the cost of your downtime vs the cost of your proposed generator. 

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1 hour ago, bitty said:

We are trying to get two going that we got from a sawmill a few years ago. We got both engines to run now to switch from 440 to 208 . Hopefully we can get one working as our normal backup has quit working. This is the bigger one it's got a 608 hp Deutz engine on it ..... 

IMG_20210119_164848639.jpg

IMG_20210119_164854824.jpg

IMG_20210119_164956606.jpg

That’s a Stamford/Newage gen end. The leads coming out will be labeled U,V,andW. When you reconfigure it the voltage will be exactly 1/2 the previous voltage. You will need to tweak the voltage regulator. Those regulators have a one turn pot and are very sensitive. Barely moving the pot can drastically change the voltage. 

If you have any questions feel free to call me (904) 616-1971. I can tell how to reconnect it or get you the diagrams if you like. Also I may be able to dig up the directions for the voltage regulator depending on which one you have.

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I was figuring to use a 275 for fuel. They have lots of hours on them as they were the only electric supply for the sawmill where they came from. The smaller one is a 8V92TA powered one . 

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Have run a bunch over the years, V16 Detroit, V16 Cummins 1MW KTA 1910 1490 hp if I recall that was a nice unit, many smaller Detroit screamers, had a couple Cat 750 kw, pretty compact units for what they put out, had some pics of the turbos cherry red with the lights turned off in the room, got a 6cyl Mitsubishi now 550kw, big old robust engine, almost obsolete now was used years ago in a lot of marine applications had to send the injection pump to Texas for repair they were the only ones left in North America to work on it

Was working on a project for 2- 1.25 MW with belly fuel tanks under the floor of the buildings, was almost $100K for their first fuel fill before Covid hit, was cheaper to build these than bring in an alternate hi voltage feed

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If we are talking fun engines.....The location we were working on the 1MW plant, they used to have a opposed piston Fairbanks-Morse 750kW back in the 60-80's.   When I was there the concrete pad was still in place....6' x 10' by 6' DEEP.....  My buddy that grew up there told me that you could feel it start up, any where on the 100 acre campus!   The ground vibrated!

Yeah, this doesn't need to be that big a deal.   Find and buy a single good backup engine with a prime rating that will handle your load.   Put in a manual switch.  Be aware that some states/localities have some pretty stringent rules about how the switch can be done, and who can install it - mostly for safety of linesmen.  You do not want to backfeed the power lines and electrocute the guys working on the wires because somebody forgot to throw a breaker.

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19 hours ago, MarkG said:

That’s a Stamford/Newage gen end. The leads coming out will be labeled U,V,andW. When you reconfigure it the voltage will be exactly 1/2 the previous voltage. You will need to tweak the voltage regulator. Those regulators have a one turn pot and are very sensitive. Barely moving the pot can drastically change the voltage. 

If you have any questions feel free to call me (904) 616-1971. I can tell how to reconnect it or get you the diagrams if you like. Also I may be able to dig up the directions for the voltage regulator depending on which one you have.

This is the road map of the wires . I am not sure how to read it but I think it would be the one circled that I need to go to . I am no good at reading wiring schematics but that looks like it will parallel the voltage to double the amps. The one that is to the left of the circled one looks like it will be twice the voltage

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The rotary dial shown here with the positions off through 3 probably increases the voltage slightly higher under load ? 

The pot is on this circuit board correct where I pointed the arrow correct

IMG_20210120_153524275~2.jpg

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